Archived posting to the Leica Users Group, 2011/12/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]sp/John McMaster/Richard Man ;-) john ________________________________________ See the link in John McMaster's post. It's clear that Leica's compression requires trivial processing. Lossless LZW or whatever would take much too much processing. Herb >Not sure if it is a processing limitation or if a firmware update can make >it lossless like the S2.... > >john > >-----Original Message----- > > >I also shoot compressed because of the write speed. I use 16 GB cards so >storage is hardly ever an issue. > >Here's a thread on the actual algorithm used, which I found somewhat >surprising. >http://www.l-camera-forum.com/leica-forum/leica-m9-forum/206098-dng-compress >ion-any-difference-quality-2.html > > I guess normal LZW / zip type of compression takes too much processing >time. Come to think of it, I'm surprised that no one in the camera industry >has designed a "compression" FPGA chip.... > >On Thu, Dec 29, 2011 at 1:53 PM, Henning Wulff ><henningw at archiphoto.com>wrote: > > > I too have never seen a difference to date. Early on I shot a number > > of comparisons to make sure I wasn't doing something stoopid, but as a > > result of those tests and information from Leica I now shoot > > compressed. It's not a matter of disk space or card space, but of > > speed. The buffer in the M9 is small enough, and clears slowly enough > > that any speed enhancement is noticeable, and there is a BIG > > difference in the speed. Try shooting a buffer full of compressed vs. > > non-compressed images and see how long it takes for the buffer to clear >(write light to stop blinking). > > > > I don't shoot in continuous mode, but I do expect the camera to be > > ready when the shot arrives in the viewfinder. When the buffer is > > full, the shot is often gone by the time the camera is ready again. > > > > Henning > > > > > > On 2011-12-29, at 12:41 PM, John McMaster wrote: > > > > > I don't think any real difference has been seen at this stage. The > > > main thing is whether future software can bring more information out > > > of a DNG file which may be lost if compressed. I shoot uncompressed > > > and deal with > > the > > > data ;-) > > > > > > john > > > > > > -----Original Message----- > > > > > > > > > Has anyone ever done a comparison of the 34.6 Mb Leica DNGs to the > > > compressed versions which are 18 Mb more or less depending on the > > > degree > > of > > > detail in the image? While it is not an issue for me, with a mere > > > 1000 to > > > 2000 images per year, terabyte drives being so cheap, It probably is > > > an issue to the much more prolific professional photographers. > > > > > > The question is: has anyone ever found an image where this degree of > > > compression has been seen to matter? > > > > > > Herb > > > > > > >_______________________________________________ >Leica Users Group. >See http://leica-users.org/mailman/listinfo/lug for more information -- Herbert Kanner kanner at acm.org 650-326-8204 Question authority and the authorities will question you.